If sp2trax is running on the same PC as Shiptrax, then use port=1515 and IP=127.0.0.1 in ShipTrax. You might have to mess around with starting/stopping in ShipTrax to get it to connect - t looks like ShipTrax doesn't release it's connection sometimes.
What I do:
1. Startup ShipPlotter, and get it running.
2. Startup ShipTrax, and make sure its setup to read port 1515 on 127.0.0.1
3. Startup sp2trax, and press the Start Server button.
It's not that friendly, but at least means we can beta test the TCP/IP side of ShipTrax.